如何从Django DeleteView发送错误消息？

假设有两种模型

Parent

和

Child

<代码>父项到子项是一对多关系

我正在为父模型创建DeleteView。在删除之前，我需要检查

父项

是否有

子项

。如果没有

子项

，则像往常一样删除

父项

模型。但如果有

子项

，则需要将错误消息发送到DeleteView确认页面

---

如何使用DeleteView实现这一点？

您可以覆盖

delete

方法并使用

DeleteView继承。您可以在子模型中添加

on_delete=PROTECTED

，并覆盖视图中的delete方法以捕获

ProtectedError

异常。有关错误消息，请参阅Django的

models.py：

class Child():
    #...
    myParent = models.ForeignKey(Parent, on_delete=PROTECTED)

views.py：

from django.db.models import ProtectedError

#...

class ParentDelete(DeleteView):
    #...
    def delete(self, request, *args, **kwargs):
        """
        Call the delete() method on the fetched object and then redirect to the
        success URL. If the object is protected, send an error message.
        """
        self.object = self.get_object()
        success_url = self.get_success_url()

        try:
            self.object.delete()
        except ProtectedError:
            messages.add_message(request, messages.ERROR, 'Can not delete: this parent has a child!')
            return # The url of the delete view (or whatever you want)

        return HttpResponseRedirect(success_url)

from django.db.models import ProtectedError

#...

class ParentDelete(DeleteView):
    #...
    def delete(self, request, *args, **kwargs):
        """
        Call the delete() method on the fetched object and then redirect to the
        success URL. If the object is protected, send an error message.
        """
        self.object = self.get_object()
        success_url = self.get_success_url()

        try:
            self.object.delete()
        except ProtectedError:
            messages.add_message(request, messages.ERROR, 'Can not delete: this parent has a child!')
            return # The url of the delete view (or whatever you want)

        return HttpResponseRedirect(success_url)